The invention relates to direct thermal printers, particularly direct thermal printers for dual-sided imaging.
Direct thermal printers are used in many applications to provide information to a user. Often, information is provided only on one side of a paper receipt. It is desirable to be able to provide variable information on both sides of the receipt to save materials and to provide flexibility in providing information. Representative documentation in the area of dual-sided thermal printing includes the following patents:
U.S. Pat. No. 5,101,222, issued to Kunio Hakkaku on Mar. 31, 1992, discloses a thermal recording material comprising a magenta-pigment layer, a yellow-pigment layer, a cyan-pigment layer, and a polyester film (PET). The thermal recording material can be heat-processed by two opposing recording heads.
U.S. Pat. No. 4,956,251, issued to Washizu et al. on Sep. 11, 1990, discloses an apparatus that can be equipped with a double thermal head, which enables simultaneous heat recording on both sides. This patent also discloses Japanese patent application (OPI) No. 208298/82, and describes the Japanese patent as disclosing printing on both sides of an opaque support.
However, these references fail to disclose a direct thermal printer for dual-sided imaging with a compact construction.
One feature of the present invention provides a compact construction by providing a first printhead in a substantially opposed relation to a second platen and a second printhead in a substantially opposed relation to a first platen. Another feature of the present invention permits activating one side of an image element prior to activating the other side.
One embodiment of the present invention relates to a direct thermal printer, which may include first and second printheads and first and second platens. The first printhead can be positioned proximate to a first platen, and a second printhead can be positioned proximate to a second platen. Generally, the first printhead is in a substantially opposed relation to the second platen and the second printhead is in a substantially opposed relation to the first platen.
Another embodiment of the present invention relates to a direct thermal printer for dual-sided imaging, which may include first and second printhead assemblies. Generally, the first printhead assembly includes a first arm coupled or formed integrally with a first printhead, and coupled to a first platen; and the second printhead assembly includes a second arm coupled or formed integrally with a second printhead, and coupled to a second platen. The first printhead can be in a substantially opposed relation to the second platen and the second printhead can be in a substantially opposed relation to the first platen.
Still another embodiment of the present invention relates to a direct thermal printer, which may include a first means for direct thermal printing positioned proximate to a first support means, and a second means for direct thermal printing positioned proximate to a second support means. Generally, the first means for direct thermal printing is in a substantially opposed relation to the second support means and the second means for direct thermal printing is in a substantially opposed relation to the first support means.